Paul di Resta is amazed he still does not know who his Force India team-mate will be for the new Formula One season.

Normally all teams have announced their line-ups going into a new year, but Force India and Caterham still each have a seat available.

At Silverstone-based Force India, reserve Jules Bianchi, former driver Adrian Sutil, and even Kamui Kobayashi, released by Sauber at the end of last season, have been mentioned.

The delay in making a decision and an announcement is all the more remarkable as the team are just three weeks away from rolling out the new car at Silverstone on February 1.

Di Resta said: "I am surprised there has been nothing yet. The team have said they will announce it in good time as to where they are going to be, and I have to respect that."

Asked whether it made any difference to him personally not knowing who he will be working alongside, Di Resta added: "Ultimately it does. But at the end of the day I know my job, and I am fully focused on what I need to achieve at the moment.

"Whether that is managing my time, booking flights, working with the engineers, or whatever. I know who my team are, who my mechanics are. There are some new faces in that, which means we will be stronger again.

"But I'm feeling quite good about it, very positive. I've been at the factory and the vibe is very high."

After the way last season ended for Di Resta, the Scot is itching to get back behind the wheel again when the first test kicks off on February 5 in Jerez.

The 26-year-old enjoyed a relatively strong campaign up until Japan, scoring 44 points, which included a career-high fourth place in Singapore.

Beyond that, however, Di Resta was unable to get to grips with his car, ending the season in ignominious fashion when he suffered his first crash to end a race in the final event in Brazil.

Ultimately, Di Resta scored just two points in the final six grands prix to finish 17 behind team-mate Nico Hulkenberg, who has since replaced Kobayashi at Sauber.

"For whatever reason nothing went the right way at the end of last season," said Di Resta.

"Essentially you always remember the end of a year more than the beginning, and with my crash as well.

"There were some good drives, some good pace, but it just never worked out.

"I've been through times like that where you just need to dig deep, and eventually you get out of it. Hopefully this year will be the year.

"Obviously, when something bad happens you just want to get back in the car the next week and go again, but there has been this lull.

"All I can say is I'm looking forward to getting in the car on the first of February, and then testing again a few days later."